The Marine Rescue Centre in Dublin picked up an alert when the man activated his Personal Locator Beacon (PLB) at about 8pm on Tuesday night.

The Waterford Coast Guard helicopter (R117) was immediately launched to the position, which was tracked to be 20 miles south off the Wexford coast.

The man was discovered sitting on the hull of an overturned yacht, and was winched to safety on the helicopter before being transferred to Waterford Regional Hospital.

Gerald O’Flynn of the Irish Coast Guard told RTE Radio One’s Morning Ireland that the yachtsman was in a “reasonable” health condition when rescued.

Mr O’Flynn added that the personal locator beacon (PLB) is a means of “electronically raising the alert”, and that the yachtsman was located within an hour of activating the PLB.

He explained that, in contrast to the emergency position indicating radio beacon (EPIRB) which belongs to an individual craft and transmits the name and position of the vessel, a PLB can be carried by an individual and triggered when they require assistance.

“It highlights the importance of the ability to communicate if you get in trouble on the sea and the capacity to stay afloat if you fall in the water,” Mr O’Flynn said.